HOLOSPIRA. 69 



Alimentary tract. The buccal mass is small, about twice as 

 long as wide, the oesophagus opening well forward. Salivary 

 glands not united, in H. roemeri rather short, and on short 

 ducts (pi. 27, fig. 39). In H. goldfussi the ducts are long, 

 according to Strebel. The fore-gut in H. roemeri (pi. 27, fig. 

 39) is slender, dark-colored, and follows the pharyngeal re- 

 tractor, lying thus near the central pillar of the shell. Pos- 

 teriorly it dilates into the stomach, which fills the greater part 

 of the upper whorl of the cylindrical portion of the shell, and 

 is copiously black-pigmented on its peripheral surface. The 

 hind-gut revolves at the suture, and is white. I could make 

 out but two longitudinal folds of the whole intestine, but from 

 the constancy of the four-folded type, and its distinct develop- 

 ment in Urocoptis (q. v.), I may have overlooked a small fold. 

 Unfortunately I have no material in condition to make another 

 examination. The liver occupies all the whorls of the cone. 



The jaw is thin, Arcuate, with a wide median projection 

 below or none. It is smooth in H. roemeri (pi. 27, fig. 38) and 

 H. nelsoni (pi. 27, fig. 40), irregularly, very finely striate ver- 

 tically in H. dalli (pi. 27, fig. 42). In H. pilsbryi (pi. 27, fig. 

 41) there are diverging, unequally spaced striae. In H. gold- 

 fussi there are distinct plates towards the edges, and elsewhere 

 a rather irregular somewhat scaly sculpture (pi. 19, fig. 50, 

 after Strebel). It varies therefore from the smooth, through 

 striated almost to the plaited type. 



The radula is about four times as long as wide, with from 

 19.1.19 teeth (in H. pilsbryi) to 27.1.27 (in H. nelsoni). The 

 transverse rows are nearly straight in the middle, bending 

 forward at the two ends. It has been examined in H. gold- 

 fussi (Binney, Strebel), H. tryoni and "pfeifferi" ( = 

 minima) (Fischer), and in H. nelsoni, pilsbryi, roemeri, eliza- 

 bethce and dalli by myself. In the species of typical Holo- 

 spira the teeth are more numerous, 17.9.1.9.17 =53 in gold- 

 fussi, 19.8.1.8.19 = 55 in nelsoni; the cusps are rather short, 

 conic, and those of the outer lateral teeth are not split, there 

 being but two (pi. 50, fig. 4, H. goldfussi, after Binney). In 

 all the other species examined the teeth are of substantially 

 the same type, varying in the length of the cusps in the several 



